A modeling process has been designed to generate protein arrangements that can be experimentally verified. It includes docking and 3D graphics and integrates biological data from crystallographic studies, chemical crosslinking, FRET, DNA nanomanipulation. Making animations of a biological process requires to know how proteins assemble. Individual structures of proteins are often known but fully assembled complexes have proved refractory to structure determination. The DNA mismatch repair system is not an exception: The key proteins MutS, MutL and MutH form an unsolved complex with the DNA that coordinates the steps of the process (identification of the mismatch (e.g. G:T) and the strand containing the erroneous base (e.g. G-strand or T-strand), excision of the strand containing the "wrongly" incorporated base). The best fitting MutSLH arrangements resulting from the modeling highlight two situations: The ternary complex can assemble on the DNA either without (sensitive to roadblocks) or with loop formation (insensitive to roadblocks). Animations can now integrate the models to inform the ways the complex discriminates the strand to nick and scans the DNA for error removal.